Rivet



Jan 209 K RIVM ifi@

Patented Jan. 20, 1925.

UNITED STATES 1,523,687 PATENT oFFlcE.

OTTO H. DE'LAPOTTERIE, OF KENT, OHIO, ASSIGNO'R TO THE LAMSON & SESSIONS COM- PANY, OF CLEVELAND, OHIO, A CORPORATION 0F OHIO.

. Application filed April 2, '1924. Serial No. 703,763.

To all whom t may concern:

Be it known that I, OTro H. Dn Lapor-A TERIE, a citizen of the 'United States, residing at Kent, in the county of Portage and' State of Ohio, have invented certain new and useful Improvements in Rivets, of which the following is a specification.

This invention relates to an improvement in rivets having a partly formed end or head.

The invention is shown in the accompanying description and in the drawings 1n which:

Figs. 1 and 2 are respectively` an elevation and a plan of the new rivet;

Figs. 3 and 4 are diagrammatic cross sections showing the rivets before and after being driven, the rivets having round heads;

Figs. 5 and 6 show diagrammatically the formation of cone and Steeple-head rivets;

Fig. 7 shows a modified form of head; and p Fig. 8 shows the manner in which the heads areV formed. f

The characteristic feature of my invention is the formation on the shank of an enlarged head which is of greatest diameter at about its median portion. Beneath this median portion which is of greater diameter 'than the shank, the head has a concave portion merging into the cylindrical shank; and above the median portion the head is formed with a similar concave portion eX- tending to an upper end-portion, which is of about the same diameter as the shank, but may be slightly smaller. The top of the rivet is preferably formed with a rounded or spherical surface and may be provided with an outwardly extending centrally located nub.

The curvature of the two concaved portions is preferably the same, these surfaces being generated by arcs of the same radius, though this and the other features described may be varied to some extent.

The median portion may be formed as a sharp ed e at the meeting of the concave surfaces, ut preferably is of some width so that there is produced what may be termed a rib.

This novel form of head for a reformable rivet has been arrived at after long experimentation and makes it possible (1) to cheaply manufacture the rivet without producing such inherent strains that the head may have a tendency to break olf after it the plates being riveted and will completely l engage the surface of the plates and make a tight joint, so that the minimum amount of calking will have to be done.

The heads above described are preferably formed cold, by dies, as shown in Fig. 8, the resulting rivet having the advantages of a truly cylindrical shank, with its end cut square, and with no fins or flashes between the lower surface of the rivet head and the plates.

As shown in Figs. l and 2, the rivet has a cylindrical shank 5, the median or ridgey portion 2, the rounded top 1, and the concave portions 3 and 4.

In Fig. 8, the rivet is shown as located within the holes of several plates 6, 7 and 8,

before being set. In Fig. 4 is shown the finished rivet after rivetin pressure has been applied to the tools 9 an 10.

n Figs. 5 and 6, tools adapted to form cone and Steeple heads, respectively, are shown, the final form of the head being shown in dotted lines.

Fig. 7 shows a modified form in which an additional nub or projection is formed on the top of the cap.

The head is formed in solid dies, as shown in Fig. 8, where 4.0 represents the blank cut oli'l from round stock, 11 a stationary die member into which the blank 1() is placed and 12 the heading tool. The orifice in the stationary die flares outwardly near its upper end defining preferably a ronvex curved surface 11a and the heading tool or hammer 12has a recess which is co-axial with the orifice in the stationary die 11 and which has a. downwardly and outwardly flaring preferably convex surface 12a similar to the convex surface 1l in the orifice.

Assuming that a blank of proper length is used,the head portion resulting from the co-operation of the die i1 and heading tool 12 has the form indicated in Figs. 2 and 3 yand the additional nub, as shown in Fig. 7,

not being essential.

This head is preferably formed cold, and it has been found that the metal of the blank, under the action of the upwardly and downwardly flaring surfaces of the compression tools flows easily into a compacted head portion without the production of flaws or strain regions, which might result in the lsubequentcracking or breaking off of the nea If the additional nub is to be formed on the top of the head, a suitable cavity is provided in the tool 12, thereb producing the reformable rivet shown in ig. 7, this form bein particularly desirable in finishing rivets o Steeple head form.

The shape given to my new reformable rivet, therefore, has the double advantage of eas and accurate manufacture, andof capabi ity of use to make a number of forms of rivet, each 'of which can be driven with the assurance that a tight joint will be effected.

In setting the rivets, which is effected in the usual manner, the pressure of the rivetsetting tools is applied axially of the rivet. This causes the s ank to expand within and fill the hole, while the metal of the head is displaced along easy lines of flow not at right angles to the axis, and because of the interspace between the Wall of the heading tool and the concaveupper portion-of the head, the displaced metal can flow before it comes into contact with the wall, with the result that the metal of the head is finally compacted into the desired shape and forced against the plate, without the formation of fins or flashes vbetween the bottom of the head and the plate.

eter of the head portion relative to the diameter of the shank, and in the radius of curvature of the concave portions may be made, Without departing from my invention, theJ general relations between theK various-size factors should be preserved. As a. guide for this purpose, the rivets, as shown in the drawings, have been drawn to scale.

I claim;

1. As an article of manufacture, arivet comprising a cylindrical shank portion and a head having a median portion ofgreater diameter than the shank and similar concave portions extending inwardly from said median portion, one of said concave portions merging With the shank portion.

2. As an article of manufacture, a rivet comprising a cylindrical shank portion-and a head having a median portion of greater diameter than the shank and similar -concave portions extending inwardly from said median portion, one of said concave portions merging with the shank portion, and the other concave portion terminating in a rounded cap portion.

3. As an article of manufacture, a. rivet comprising a cylindrical shank portion and a head having a median portion of greater diameter than the shank and similar concave portions extending inwardly from said median portion, one of said concave portions merging with the shank portion, and the other concave portion terminating in a rounded cap portion, the diameter of the base of the cap portion being substantially the same as the shank.

4. As an article of manufacture, a rivet comprising a cylindrical shank portion land a head having a median portion of greater ldiameter than the shank and Asimilar concave While obviously vvariations in the diam-4 portions extending inwardly from said median portion, one of said concave portions merging with the shank portion, and the other concave portion terminating in a rounded cap portion, said cap portion being provided with a centrally located nub.

In testimony whereof, I aix my signature. Y

OTTO H. DE LAPOTTERIE. 

